Firearm and alloy for making same



To all whom it may concern: I Be it known that I, FRANK A. FAHREN- WALD,acitizen of the United States, resid- I ing at Cleveland, in thecounty-oi Guyahoga and State of Ohio, have invented a certain new anduseful Improvement-in Firearms and Alloys for Making Same, of which thefollowing is a full, clear, and exact description. f

, This invention relates to firearm and ordnance and has for itsparticular object the provision of a metallic alloy for use in theconstruction of the same which shall. be

more resistant to corrosion by the combustion products of theexplosive,as well as less corrodedv by atmospheric conditions, salt solutions.(such as sea water or sweaty hands), than anything previously used forthe purpose, as well as having suflicient mechanical strength to endurethe strains to which such devices are subjected, and at the same timebeing sufliciently soft and workable for manufacturing purposes.

It is well known that powder gases, particularly those of the presentday smokeless and high explosive powders, are extremely corrosive-tosteelbarrels so that the latter become rapidly etched and pitted. Thiscircumstance has greatly shortened the life of sporting arms and hasrendered very onerous the maintenance of-military arms of all calibers,since not only have the metals heretofore employed sufl'ered greatly bythe instant erosion of the hot gases but the powderresidues are of anequally great ,cor-

rosiveness and cannot be removed by mere h sical. means nor even b a sinle a 1iation of chemicals. Unlesis such a firgzii'm be cleaned within atleast an hour after each shot,t'he barrel interior becomes noticeablyetched, and even a few verysmall pits seriously impairs the accuracy ofthe gun. Likewise the exteriors of the barrels and the surfaces of theoperating mechanism become rapidlylfiorroded by atmospheric influencesand s used at the present day are jacketed with some alloy which willkeep the lead from melting and will engage the rifling properly.

ture, velocity and pressure, thus producing f Specification of LettersBatu t. Application meanu m a, 1919. Serial No.

I contact unless frequently oiled. Furthermore, most high velocity riflebullets PATENT ounce;

thev phenomenon known as Fmetal fouling," which means a slow accretioninside the bare rel of substance taken from the bullets, which alwaysinterferes seriously withv the accuracy, and frequently leads tobursting of theb'a'rrel: j

Numerous alloys have. heretofbre heen known which would resist thechemical. action to the necessary "extent, (such. as alloys of platinum,gold-palladium, and the meat-am lgam like precious metals), but thephysical requirements of firearms metal are also pe-' culiarly exactingsince it-must be sufficiently soft and uniform to permit of ready boringand rifling of the barrel and fashioning of v the operating mechanism,and yet possess sufiicient toughness-and mechanical strength to resistthe explosion pressures and the mishaps to which such. devices arenecessarily sub'ected in use.

The ob ects of my invention are, there-- fore, the provision of an alloyfor the purposes stated having the requisite chemical resistivitycoupled with the necessary physical strength; the provision of an alloywhich shall not be subject to metal fouling; the provision of an alloywhich can be readilyforged, machined 'and worked into shape; theprovision of an alloy of reasonably low alloy wor able process; whilefu'rtherobjects and advantages ofmy invention will become apparent asthe description proceeds.

My improved alloy consists essentially of one or more iron' roup metalscombined with one .or more c romium group metals. Carbon and silicon maybe present in case their quantities are small, say, .5 or less; a smallamount of manganese is preferably employed because of its value inscavenging oxygen and sulfur and because of the fact that bettercastings are secured with its use. The tensile strength of the alloy canbe increased slightly by.the addition of a small amount of copper,tatalum, vanadium, zirconium, or titanium, although the strength of thesimpler alloy is sufficiently great so thatno particular advantage issecured by their use. All these minor modifications fall within thescope of. my generic idea and the presence or absence of theseadditional substances does not modify my invention.

As examples of alloys which embody my which can be made by a simple andNickel 55 (10-55; a Chromium -15 8-20 Iron 30 282-25; Iron 75 60-90lChromium 25 (1040) Nickel 85 (70-95 Chromium 15 (-30 Nickel 90 (85-95)lTungsten or molybdenum 1O 5-15) Iron 90 (80-95), {Tungsten ormolybdenum" 5-20) Any two iron group metals..- 9O 75-95) {Tungsten ormolybdenum 10 5-25) Any two iron group metals 70-90 g Chromium and oneother metalv from chromium group 10-30, ron or nickel 70-90 75, Cobalt5-20. Chromium or tungsten 5-25,- It will be understood that theforegoing position within that group theses indicating the permlssiblevarlatlons. I

invention, I will instance the following, the first column indicatingthe preferred com-. and the paren formulas are not intended to includeall the ingredients present in the alloys, s1'nce small amounts ofcarbon, silicon, and manganese will almost always be present, and smallquantities of certain addltional metals may sometimes be added such ascopper etc. as has already been" suggested. It is only necessary thatthe percentage of carbon and silicon be kept sufliciently low, such as.5% or less of each, to prevent the metalfrom being too hard to work,and that sulfur and phosphorus be avoided.

The requirements of dlfi'erent guns are so various, especially when low1ntrms1c value is considered as a requirement, that no one alloy can bedenominated a preferred species for alluses, Thus thealloy of group acontaining nickel 5 5%, chromium 30% and iron 15%,-exh1b1ts everydesirable chemical and mechanical property in the highest degree. It canbe made wlth comparative ease in the electric furnace.or by thealumino-thermic method 11; makes a good casting, can readily be forgedor rolled at a bright red heat, and can be bored, turned, rifled, andshaped without difiiculty. The gases and residues of smokeless powder donot etch it even n days of neglect, rain does not rust 1t, and polishedbarrels buried in the ground for weeks exhibit only a slight superficialtarnish which can be wiped off with the hand.

Bullet jackets of iron, nickel, or their alloys do not foul it, and itstensile strength is so high that it compares well withthe steelsordinarily used. This alloy is good enough for almost every purpose butcan be only slightly improved by the addition of a little molybdenum ortungsten which will still further increase the chemical resistivity.

- The only drawback is that it is unnecessarily good for some purposes.For example in a .22 caliber boys rifle, the bursting strainsare sosmall as to be withstood by any metal which is stron the mechanicalshocks 0? cheaper allo s can be found which will possess chemicaresistivity without such an excess of mechanical strength.

For example the percentage of iron can be increased as shown under a orthe nickel portion that nickel is superior to iron in chemicalresistivity. Owing to the hardening effect of chromium thereon theproportion of the latter is decreased. It will be understood that cobaltcan be employed in substitution for iron or nickel or-in'additionthereto, although no advantage in its use ofi'sets its high price.

If tungsten or molybdenum be emplo ed in place of chromium in c, Isecure the a loy shown at d which is also hard, strong and chemicallyresistant; or if the chromium in 6 1s replaced by tungsten or molybdenumI secure the alloy. shown at e which is also of value for firearms. Inthese cases the amount of thetungsten-like metalis decreased owing toits hardening effect.

I fin'd the ternary alloys better than the binary alloys for thispurpose, wherefore I prefer the compositions shown in a, f, or g, or onemade by adding tungsten or molybdenum to b or c. In fact for somepurposes the very best alloy appears to be a quaternaryas produced byadding tungsten or molybdenum to a or chromium to f. I do, however, findthat the essential elements are those contained in the iron and chromiumgroups of the periodic table and that at least one metal from each groupshould be used;

also the chromium group metal should occur to an amount of at leastabout 5% and should not go above about 25% unless the iron group metalbe iron alone and the chromium group metal be chromium alone in whichcase the percentage of the latter can be increased up to about 40%without rendering the alloy too hard to work.

enough to resist use. Other and It will be understood that while my-im-I proved alloy is specially devised for manually portable arms such asrifles and shotguns it is equally good for pocket devices such asrevolvers or for ordnance of large sizes; that the barrels can be madefrom a singlehomogeneous piece of the material, or

that a composite ingot may be made, or a built up barrel employing myimproved alloy as a lining; that my alloy can be used for lockmechanisms equally with the barrels'; and that I desire my claims takenin the broadest sense that their language will support.

' Having thus described my invention what I claim is 1. A firearm barrelmade from an alloy of one 'or more iron group metals combined with oneor more chromium roup metals.

2. -A firearm barrel made l r om an alloy of one or more iron groupmetals combined with one or more chromium group metals,

the latter being present to an amount of at least 5%.

3. A firearm barrel made from an alloy of two iron group metals togetherwith at least one chromium group metal. 20-

4. A firearm barrel made from an alloy of two iron group metals togetherwith chromium and another metal from th chromium group.

5.'A firearm barrel made from an alloy containing at least 5% ofchromium, at least 5% of nickel and not more than 90% of iron.

6. A firearm barrel made from an alloy containing between 5% and 25% ofone or more metals of the chromium group combined with metals of theiron group, not more than 90% of the whole alloy being iron.

7. A firearm having a barrel composed of or lined with an alloy of iron,nickel and chromium wherein the chromium and nickel each comprises notless than about 10% of the whole.

8. A firearm having a barrel composed of I or lined with an alloy ofiron, nickel and the balance mostly chromium.

9. A firearm having a barrel composed of or lined with an alloy of iron,nickel and chromium, wherein the iron constitutes not over about 40%,chromium between 15% and 20% and the balance mostly nickel.

10. A firearm having a barrel composed of or lined with 'an alloy ofiron, nickel and chromium wherein the iron constitutes about 30%, thechromium between 15% and20% and thebalance mostly nickel.

11. A firearm having parts made ofan alloy containing less than about80% of iron alloyed with more than 10% of nickel and at least 8% ofchromium.

12. A-firearm having parts made of an alloy comprising between 8% and20% chromium, together with between about 25% and about 80% iron, thebalance being principally nickel.

13. A firearm having parts made of an alloy whose principal ingredientsare iron,-

' alloy containing less than 80% of iron combined with more than 10% ofchromium, the balance consisting largely of other metals from the ironand chromium groups.

15. A firearm having parts made of, an alloy containing less than 90% ofiron combined with at least 5% of a metal from the chromium loyconsisting principally of other metals from the iron and chromiumgroups.

16. A firearm having a barrel composed of or lined with an alloycontaining between 30% and 90% of iron, and at least 10% of chromium,any remainder of the alloy consisting principally of nickel.

17 A firearm having a barrel composed of or lined with an alloycontaining not over 90% of iron and not less than 10% of portion ofbetween 75% and 90% combined with chromium group metals, chromium itcup,any remainder of the al- I self constituting at least one-half of thebalance.

21. A firearm barrel made of an alloy containing iron combined with atleast ten per cent. of one or more of the metals nickel and chromium.

22. A firearm barrel made of analloy containing between abouttwenty-five per cent. and about ninety per cent. of iron, the balancebeing principally nickel and chromium and carbon being present .to. anamount not greater than two tenths of one per cent.

23. A firearm barrel made of an alloy characterized by the presence ofmore than ten per cent. of one or both of the metals nickel andchromium.

24. A firearm barrel made of an alloy containing one or more iron groupmeta-ls alloyed with such an amount of chromium that the total amount ofnon-ferrous metal in the alloy shall constitute at least about ten percent. of the whole.

25. A firearm barrel made of an allo of one or more iron grou metals witchromium, the amount of c romium bein such as together with thenon-ferrous meta of the alloy shall constitute at least ten per cent. ofthe whole.

26. A firearm barrel made of an alloy consisting essentially of ironwith either or both nickel and (or) chromium, the highest limitofchromium being about twentyfive per cent. and the highest limit ofiron being about ninety gel cent; and the lowest limit of nickel or cromium or some combination of the two being not less than 10 about tenper cent.

In testimony whereof I hereunto affix my signature.

FRANK A. FAHRENWALD.

